<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <div v-if="isLogin">
    <!--javascript:void(0)禁止超链接的跳转功能-->
    <a href="javascript:void(0)" >注册</a>
    <a href="javascript:void(0)" @click="isLogin=false">登录</a>
  </div>
  <div v-else>
    <input type="text" placeholder="名字" v-model="newName">
    <a href="javascript:void(0)"  @click="arr.push(newName)">添加</a>
    <a href="javascript:void(0)" @click="isLogin=true">登出</a>
  </div>
    <ul>
      <li v-for="name in arr">{{name}}</li>
    </ul>

</div>
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<script>
  let v = new Vue({
    el:"body>div",
    data:{
      isLogin:true,
      arr:["刘备","关羽"],
      newName:""
    },

  })
</script>
</body>
</html>